Land mine



Nov. 9, 1965 M. P. BEARCE 3,216,354

LAND MINE Filed July 10. 1952 Marshall P. Bear-1:5

United States Patent 3,216,354 AND MINE Marshall P. Bearce, FallsChurch, Va., assignor to the United States 0t America as represented bythe Secretary of the Army Filed July 10, 1952, Ser. No. 298,213 13Claims. (Cl. 102-8) (Granted under Title 35, US. Code (1952), sec. 266)This invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to me ofany royalty thereon.

This invention relates to improvements in land mines and moreparticularly to such a mine adapted to be concealed and camouflaged bybeing buried beneath the surface of the earth and is actuated uponcontact with a vehicle by a fuze attached to the mine.

The high explosive charge in a mine of the type disclosed in thisdescription is usually shaped for armor piercing in accordance with ashaped charge effect. Previous tests have proven that even a smallamount of earth covering the mine can result in failure of the charge topenetrate even a small thickness of armor. By the use of a mineconstructed in accordance with this invention the effectiveness of themine is retained even when concealed or covered with a layer of earth ofsubstantial thickness.

It is a primary object of this invention to provide a small preliminaryor clearing charge just below the cover of the mine which will beignited a short time ahead of the high explosive charge, to clear awaythe earth covering the mine to allow the full unobstructed efiect of themain charge.

It is a further object to increase the effectiveness of the mine againstarmor and the like.

The specific nature of the invention as well as other objects andadvantages thereof, will clearly appear from a description of apreferred embodiment as shown in the accompanying drawings in which:

FIGURE 1 is a fragmentary top plan of a mine embodying the invention;and

FIGURE 2 is a vertical section taken along lines 2-2 of FIGURE 1.

Referring more particularly to the drawing wherein like referencecharacters designate like or corresponding parts throughout thedifferent views, 1 designates the mine generally in its entirety andwhich includes a cylindrical high explosive charge container formed by aside wall 2, a top wall 3 and a botom wall 4. Side wall 2 is flangeddownwardly at its upper edge to form a support 7 for a dishshaped plateor cover member 8, usually of frangible or malleable material, and whichforms a retainer or liner for the high explosive shaped charge 20. Topwall 3 is centrally depressed as at 5 to form a well which is providedwith an opening 6 at its bottom for a purpose to be hereinafterdescribed. Bottom wall 4 is provided with a central opening 10 in axialalignment with an opening 9 in plate or liner 8. The plate 4 is struckup at its control opening to form a flange 11. A fuze well 13 ispositioned centrally within the mine body, one end of which fits snuglywithin opening 9 while the other end is flared and flanged as at 12 tofit tightly over flange 11 in bottom wall 4, thus forming a closedcontainer for the high explosive charge 20. Contained within the fuzewell 13 are the operating elements of the detonator consisting of afiring pin or member 14 adapted to strike upon pressure, a primer 15. Adelay element 16 and a booster charge 17 complete the firing train.These elements are held within the fuze well by a threaded cap 18threaded into a bushing 19 fitted into the flanged portion 11 of bottomwall 4.

Fitted snugly within the well 5 of the top wall 3 is a container elementdesignated generally by 21 comprising a cup-like container 22 closed bya tight fitting cover or cap 3,216,354 Patented Nov. 9, 1965 23externally threaded for engagement with a sealing ring 25 to form atight container for a small powder charge 26. Ring 25 is secured as bysoldering to wall 3 coaxially of the opening therein. Provided centrallyof the cap 23 is an annular flange 27 internally threaded as at 28 toreceive a threaded plug 29 provided at its upper end with an externallythreaded boss 28a. The plug 29 is centrally bored at 30 to receive aprimer 31 and a flash passage of reduced diameter opening into thecontainer 22.

Threaded upon the boss 28a is a detonator indicated generally by 32which may be of a well-known construction of the type used to detonateanti-tank or anti-personnel mines. The housing 33 of detonator 32,encloses the head 35 of an operating rod 34a. As shown upon FIG- URE 2,head 35 is in contact with a firing pin member 36, which member is urgedupwardly and held with its depending pin just above primer 31, by aBelleville spring 37. This spring has its periphery clamped between thetwo halves of housing 33, as clearly shown.

Rod 34a extends upward through a central aperture in the top part ofhousing 33 and thence through a central bore in a radially slottedsafety clip 40 which rests upon, but is not attached to, an aperturedcap threaded onto the upper part of housing 33. A safety pin 38 extendsthrough aligned transverse holes in clip 40 and rod 34a to preventpremature actuation of the mine and has a ring 41 to facilitatewithdrawal of the pin to effect arming of the mine.

A ring 42 is fixed to the top end of rod 34a coaxially thereof. Thisring has a plurality of circumferentiallyspaced holes as clearly shownupon FIGURE 1 to enable the attachment thereto of one or moreradially-extending trip Wires, when and as desired. The ring is fixed torod 34a by a bushing 42a which provides a socket to removably receive anelongated tilt rod 34. This rod may be of the order of several inches inlength and, when in position on a mine, will be engaged by a tank orother object passing thereover, to eflect tilting of rods 34, 34a andhead 35 to detonate the mine, as subsequently described. Line A, FIGURE2 indicates the approximate level of earth when the mine is properlyplaced.

In operation, after the mine is buried to the approximate depthindicated, safety pin 38 is withdrawn and clip 40 is removed to arm themine. When a vehicle or other moving objects strikes rod 34 to tilt itfrom its vertical position the rod is cammed downwardly by the action ofhead 35 conjointly with the annular shoulder of the upper part ofhousing 33. This movement forces firing pin 36 downwardly, flexingspring 37 until the latter snaps into downward position thus driving thefiring pin into primer 31 to initiate clearing charge 26. The blast ofthis preliminary or clearing charge (1) blows off the concealing layerof earth, cover 3 and the parts carried thereby and (2) drives firingmember 14 downwardly into primer 15 to initiate the same. Delay train 16is then set oif, followed by booster charge 17 and main charge 20. Asthe main charge now has a clear, unobstructed path to the object, thefull force of the shaped charge is effective upon the vehicle or otherobject and maximum destructive effect is obtained. The chances ofcrippling or destroying the vehicle or other object are thereby greatlyincreased. The delay train 16 determines the time period betweeninitiation of preliminary charge 26 and is so prepared that main charge20 will be detonated after the covering earth and wall 3 with partscarried thereby, have been blown out of the way.

I have thereby provided a land mine which is therefore highly effectiveagainst armored vehicles but which, at the same time, may be adequatelyconcealed while giving the increased destructive elfect to the vehiclefor the weight and type of charge utilized.

While I have .shown the preferred form of the invention as now known tome, various modifications and substitutions of equivalents will occur tothose skilled in the art after a study of the foregoing disclosure.Hence, the disclosure should be taken in an illustrative rather than alimiting sense; and it is my desire and intention to reserve allmodifications within the scope of the subjoined claims.

Having now fully disclosed the invention, what I claim and desire tosecure by Letters Patent is:

1. In a land mine, a bottom, side walls and cover member united to forma closed container, a main explosive charge in said container,percussion firing means exposed through an opening in said cover memberand in detonating relation with said main charge, a preliminaryexplosive charge, means mounting said preliminary charge over saidpercussion firing means in fixed percussive relation therewith, andmeans fixed with said container for firing said preliminary charge onlyin response to passage of a target thereover.

2. In a land mine, a closed container including an apertured covermember, a main explosive charge in said container, percussion firingmeans in said container in detonating relation with said main charge andincluding a delay train, a preliminary explosive charge, means mountingsaid preliminary charge over said percussion firing means in fixedpercussive relation therewith, and contact firing means fixed with saidcontainer in superposed relation over said preliminary charge and indetonating relation therewith, detonation of said preliminary chargeclearing the earth covering the mine and providing a clear path betweenthe main charge and target.

3. In a land mine, a closed container including an apertured top member,a main explosive charge in said container, a detonator having apressure-responsive firing means exposed through said aperture and indetonating relation with said main charge, said detonator including adelay train and a booster, a preliminary clearing charge, means mountingsaid clearing charge in fixed relation over said pressure-responsivefiring means in percussive relation therewith, a contact firing device,and means mounting said contact firing device in fixed position on saidcontainer and in detonating relation with and superposed over, saidpreliminary charge.

4. A land mine comprising a closed container including a top wall, anupwardly-facing shaped explosive main charge within said container, apreliminary explosive charge carried by said top wall above said maincharge, an impact-operated fuze carried by said top wall in superposeddetonating relation with respect to said preliminary charge, and a fuzein said container in detonating relation with said main charge andincluding a firing member responsive to the blast of said preliminarycharge.

5. A land mine as recited in claim 4, said last-named fuze including adelay train between said firing member and main charge.

6. In a land mine, side, bottom and top walls united to form a closedcontainer, an upwardly-facing main explosive shaped charge fixed in saidcontainer, a frangible liner fitting said shaped charge and having acentral opening, a central well in said top wall having an aperture inits bottom over and in vertically spaced relation from the opening insaid liner, a preliminary explosive charge confined in said well, animpact fuze carried by said top wall in superposed position over saidpreliminary charge to detonate said preliminary charge in response topressure of an object passing thereover, a second fuze fixed within acentral vertically disposed passageway in said main charge, said centralsecond fuze including a detonator exposed through said opening andactuated in response to detonation of said preliminary charge, and adelay train and booster interposed between said detonator and maincharge, detonation of said preliminary charge acting to blow away theearth concealing the mine to provide an unobstructed path between saidmain charge and object.

7. In an explosive unit, such as a land mine, for concealment belowground, a main explosive charge, a preliminary explosive charge, meansmounting said charges with said preliminary charge in superposedrelation with said main charge, a detonator in superimposed relation tosaid preliminary charge for initiating said preliminary charge inresponse to passage of a target thereover, and means disposed beneathsaid preliminary charge responsive to detonation of said preliminarycharge to detonate said main explosive charge after a predeterminedminimum time.

8. In a land mine, comprising a closed container having a dish-shapedhigh explosive charge received therein, a frangible liner engaging thetop surface of said explosive charge, a first fuse including a delaytrain received in said container in detonating relation with saidexplosive charge, means in said container in superposed spaced relationwith said first fuse for initiating action of said first fuse, aclearing charge supported by said container in spaced relation abovesaid initiating means, and a second fuse carried by said container, insuperposed position over said clearing charge and initiated by a passageof an object thereover to detonate said clearing charge, said first fuseinitiating means being movable to fuse detonating position by the blastfrom said clearing charge, detonation of said clearing charge acting toblow away earth concealing said land mine to provide an unobstructed.path between said lined high-explosive charge and said object.

9. In a land mine, comprising a closed container having a dish-shapedhigh explosive charge received therein, a frangible liner contacting theupper surface of said charge, a first fuse including a delay train insaid container in detonating relation with said explosive charge, anaxially movable firing pin in said container in superposed spacedrelation with said first fuse for initiating action of said first fuse,a clearing charge supported by said container in spaced relation abovesaid firing pin, a second fuse carried by said container in superposedposition over said clearing charge and initiated by the passage of anobject thereover to detonate said clearing charge, said firing pin beingmovable to fuse detonating position by the blast from said clearingcharge, detonation of said clearing charge acting to blow away earthconcealing said land mine to provide an unobstructed path between saidlined high explosive charge and said object.

10. In a land mine, comprising a container formed by a side wall, a topwall and a bottom wall, a high-explosive charge in said container havinga concave upper surface, a detonating fuse including a delay trainembedded centrally within said high-explosive charge, said top wallbeing centrally depressed to form a well having an opening in itsbottom, a firing pin in said container in superposed spaced relationwith said detonating fuse and lying :below said opening, a clearingcharge within said well, and a fuse supported by said top wall insuperposed relation above said clearing charge and initiated by thepassage of a target thereover to detonate said clearing charge, saidfiring pin being movable to position to initiate action of saiddetonating fuse by the blast from said clearing charge.

11. A land mine according to claim 10, and includ-' ing a frangibleliner for said concave surface, detonation of said clearing chargeacting to blow away earth concealing said mine to provide anunobstructed path to said target for said liner and high-explosivecharge.

12. A land mine according to claim 10, and including a cup-likecontainer in said well for receiving said clearing charge, a lid adaptedto be fitted over said cup-like container, said lid having an externallythreaded upper peripheral edge, and a sealing ring threadably engagingsaid externally threaded lid and providing a seal between said cup-likecontainer and said top wall.

13. A land mine according to claim 10, there being a References Cited bythe Examiner central opening formed in said lid and having an upstand-UNITED STATES PATENTS ing internally threaded Wall integral with saidlid, an insert screw-threadedly received by said upstanding wall B i: eta1 5 and having an upwardly-extending threaded tenon, there 5 av2,457,817 1/49 Harrell 1027.2 being an axial bore formed in said insertfor recelving a 2,488,547 11/49 Lil egren 102-8 pruner, there also belnga continuation of said axial bore 2 667 836 2 /5 4 Church et a1 102 20communicating at one end with said primer and at its other end with saidclearing charge, and an upstanding housing FOREIGN PATENTSscrew-threadably engaging said tenon, there being a 10 574,132 12/45Great Britain. firing pin in said housing actuable to detonate said670,852 4/52 Great Britain. primer, said last-named firing pin and saidprimer com- 670,853 4/52 Great Britain.

prising said target responsive fuse for detonating said BENJAMINA'BORCHELT Primary Emmi-mm cleanng charge- 1 SAMUEL BOYD, SAMUELFEINBERG, Examiners.

2. IN A LAND MINE, A CLOSED CONTAINER INCLUDING AN APERTURED COVERMEMBER, A MAIN EXPLOSIVE CHARGE IN SAID CONTAINER, PERCUSSION FIRINGMEANS IN SAID CONTAINER IN DETONATING RELATIN WITH SAID MAIN CHARGE ANDINCLUDING A DELAY TRAIN, A PRELIMINARY EXPLOSIVE CHARGE, MEANS MOUNTINGSAID PRELIMINARY CHARGE OVER SAID PERCUSSION FIRING MEANS IN FIXEDPERCUSSIVE RELATION THEREWITH, AND CONTACT FIRING MEANS FIXED WITH SAIDCONTAINER IN SUPERPOSED RELATION OVER SAIDD PRELIMINARY CHARGE AND INDETONATING RELATION THEREWITH, DETONATION OF SAID PRELIMINARY CHARGECLEARING THE EARTH COVERING THE MINE AND PROVIDING A CLEAR PATH BETWEENTHE MAIN CHARGE AND TARGET.